A conventional aircraft brake comprises a coaxial stack of friction disks, which are called rotors and stators.
The rotors are rotated by the rim of the wheel, via a plurality of pins located on the interior of the rim and parallel to its axis. They can consequently slide with respect to the rim.
By an identical principle, the stators are linked in rotation with the wheel axle, whilst being able to slide with respect to said axle.
The rotors and stators are stacked in an alternating manner and it is merely necessary to axially compress the system for braking to take place. This compression is brought about by a plurality of hydraulic jacks arranged axially on a circumference having a diameter close to the mean diameter of the friction or rubbing faces of the disks. This plurality of jacks is fixed to the wheel hub. Opposite to the stack of disks with respect to the jacks are also fixed to the wheel hub a certain number of support points centered on the mean diameter of the rubbing faces of the disks.
In order to control friction, only half the number of Jacks is used, the other half serving as a standby, security system. However, there is nothing to distinguish the two groups of jacks, which are also arranged in alternating manner on the circumference.
In the prior art, the jacks bear directly on the face of the first stack of the disk, which is always a stator because it must not slide with respect to the jacks.
The aim of this configuration is to gain weight. For the same reason the number of jacks arranged in circumferential manner is as small as possible. For a commercial airliner there are e.g. in general 10 to 14 jacks, i.e. 5 to 7 simultaneously active jacks.
Bearing in mind the diameter of the disks, the distance between the active jacks is consequently approximately 20 cm. This distance is considerable compared with the thickness of the disks, so that there is a very significant pressure variation between the disks as a function of the jack spacing. When the disks are made from carbon and more particularly good heat conducting carbon, so that they are not very hard, this pressure heterogeneity is responsible for an increase in wear.
This pressure heterogeneity also leads to temperature heterogeneities and more particularly to very hot zones in the extension of the axis of the jacks. As the friction coefficient of carbon and many friction materials decreases greatly with the temperature, there is a very significant reduction in the stopping performance, particularly in the case of an aborted take-off.
The object of the invention is to very significantly reduce the pressure heterogeneity, whilst only adding a relatively small mass or weight to the already produced brake.